I had done all of those recently(except different browsers; I'm using Firefox), I think after my previous failed install attempts, but not since I started with this round of install attempts.
I just find it curious that I can install TP OK into a new test forum I set up in a different hosting account -- also a shared hosting, Linux account @ Godaddy. But, I suppose some different things happen with various index and settings files and such in different installs.
EDIT: And it looks like Porky got it covered. Thanks!